1.11 Consider the various definitions of operating system. Consider whether the operating sytem should include applications such as web browsers and mail programs. Argue both pro and con positions, and support your answers.
2.3 What are the differences between a trap and an interrupt? What is the use of each function?
2.5 Which of the following instructions should be
a. Set value of timer
b. Read the Clock
c. Clear Memory
d. Turn off interrupts
e. Switch from user to monitor mode
2.6 Some computer systems do not provide a privileged mode of operation in hardware. Is it possible to construct a secure operating system for these comptuers? Give arguments both that it is and that it is not possible.
2.8 Protecting the operating system is crucial to ensureing
that the computer system opeartes correctly. Provision of
this protection is the reason for dual mode opeartion,
memory protection, and the timer. To allow maximum
flexibility, however, you should also place minimla
constraints on the use.
The following is a list of instructions that are normally protected. What is the minimal set of instructions that must be protected?
a. Change to user mode
b. Change to monitor mode
c. Read from monitor memory
d. Write into monitor memory
e. Fetch an instruction from monitor memory
f. Turn on timer interrupt
g. Turn off timer interrupt
3.9 Why does Java provide the ability to call from a Java program native methods that are written in, say, C or C++? Provide an example where a native method is useful.